Jewish leaders in the Chicago area said they fear placards at two recent pro-Palestinian rallies that twist the Star of David into a Nazi swastika and compare the deaths in Gaza to the Holocaust inspired a string of attacks in the last two weeks on several synagogues and a school.

The “blatant anti-Semitic language” at the rallies, which were held Jan. 2 and Jan. 9, have delayed a collaboration between local Jews and Muslims to draft principles for civil discourse on the Middle East conflict, they said.

Organizers of the pro-Palestinian rallies said they don’t condone the vitriol in the placards. Some condemn it. But some say complaining about cardboard won’t solve the humanitarian crisis unfolding in the Middle East.

“I think both the protesters who exaggerate the message out of emotion or to draw attention—as well as their critics who jump on it to score a ‘gotcha’— are distracting from the real and tragic humanitarian crisis at hand,” said Ahmed Rehab, executive director of the Council for American Islamic Relations.

At a news conference in support of Israel this week, Jewish leaders called attention to the offensive signs and slogans at the rally as well as recent attacks on area synagogues where vandals spray-painted “Death to Israel” and “Free Palestine.”

“The organizational sponsors of these rallies have a civic obligation to make sure the imagery, the chanting, the tenor of their gatherings remain prejudice- and bias-free and don’t serve as venues for incitement and further divisive sentiments between communities,” said Jay Tcath, senior vice president of public affairs for the Jewish United Fund/Jewish Federation of Metropolitan Chicago.

Anti-Zionism is the new anti-Semitism, Tcath said.

“Rejecting the right of the Jewish people of having a Jewish state is the new and most dangerous form of anti-Semitism,” he said. “It’s in that context in which these signs are being seen by myself.”

In addition to placards, protesters also waved flags of the militant Palestinian Islamist group Hamas and the equally militant Lebanese Islamist group Hezbollah, which aim to eliminate Israel as part of their mission statements. One banner touted the debunked conspiracy theory that Jews were responsible for the terrorist attacks of Sept. 11, 2001.

Rehab agrees that rally organizers should have confiscated offensive signs. But he said the point of the rally shouldn’t get lost.

“As hundreds of innocent human lives are crushed in full view of the world by a belligerent Israeli government, I find it appalling that some on the pro-Israeli side are better concerned with cardboard paper,” he said.

But like other forms of hatred, anti-Semitism also can transcend words. Jenna Benn, assistant director of the Anti-Defamation League in Chicago and the Upper Midwest, said incidents of vandalism and harassment have dramatically increased in recent weeks—a ripple effect similar to the one seen in 2006 during the Lebanon war.

Six Jewish institutions have been vandalized in recent weeks, including one arson attempt. On one college campus, a Jewish student was called a Nazi, Benn said.

The Council of Islamic Organizations of Greater Chicago has condemned the synagogue attacks.

“There’s a fine line between what’s anti-Israel and what’s anti-Semitic,” she said. “If the U.S. were being repeatedly attacked from Canada by rockets, we would retaliate, whereas Israel doesn’t have that right . . . Comparing Jews to Nazis [is] problematic.”

But Stephanie Weiner, who organized Thursday’s protest of Chicago’s ties to Petach Tikva, one of Chicago sister cities, simply doesn’t want Chicago to support what she believes are war crimes. Seven miles east of Tel Aviv, Petach Tikva was one of the first exclusive Jewish settlements in Israel. Weiner and about five protesters distributed leaflets to guests at a breakfast hosted by Mayor Richard Daley.

“This has nothing to do with religion,” she said. “People who know and care know it’s a human-rights issue.”